body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
  }
  
  nav {
    background-color: #333;
    color: white;
    padding: 10px;
  }
  
  nav a {
    color: white;
    text-decoration: none;
    margin-right: 15px;
  }
  
  .login-container {
    text-align: center;
    padding: 50px;
  }
  
  .conversation-container {
    padding: 20px;
  }
  
  .conversation-history {
    border: 1px solid #ccc;
    padding: 10px;
    margin-bottom: 10px;
  }
  
  .diary-container {
    padding: 20px;
  }